Accompanied with overwhelming advancement of touch sensing techniques, a touch display panel becomes more and more prevalent in electronic devices. The touch display panel offers visual feedback and allows a user to manipulate the electronic device via touch inputs.
Compared to conventional user input devices such as a keyboard or buttons of an electronic device, the touch display panel provides relatively unsatisfactory touch feedback. More specifically, when a user performs touch inputs, a sense of contact at a fingertip or at a touch control pen may not be as apparent such that it is difficult for a user to certain whether a desired touch input is completed or to identify the number of contacts. Thus, a user often relies on visual feedback provided by the touch display panel to acquire an outcome of the touch input. However, this imposes extra visual loading on a user while also reduces manipulation conveniences of the electronic device.